Luteal Phase in Assisted Reproductive Technology

Androgen receptor gene deficiency results in the reduction of steroidogenic potential in porcine luteal cells

Luteal steroidogenesis is critical to implantation and pregnancy maintenance in mammals. The role of androgen receptors (AR) in the progesterone (P4) producing luteal cells of porcine corpus luteum (CL) remains unexplored. The aim of the present study was to establish AR gene knock out (KO) porcine luteal cell culture system model by CRISPR/Cas9 genome editing technology and to study the downstream effects of AR gene deficiency on steroidogenic potential and viability of luteal cells. For this purpose, genomic cleavage detection assay, microscopy, RT-qPCR, ELISA, annexin, MTT, and viability assay complemented by bioinformatics analysis were employed. There was significant downregulation (p < 0.05) in the relative mRNA expression of steroidogenic marker genes STAR, CYP11A1, HSD3B1 in AR KO luteal cells as compared to the control group, which was further validated by the significant (p < 0.05) decrease in the P4 production. Significant decrease (p < 0.05) in relative viability on third passage were also observed. The relative mRNA expression of hypoxia related gene HIF1A was significantly (p < 0.05) downregulated in AR KO luteal cells. Protein-protein interaction analysis mapped AR to signaling pathways associated with luteal cell functionality. These findings suggests that AR gene functionality is critical to luteal cell steroidogenesis in porcine.

Time-sensitive assessment of luteal phase progesterone after HCG ovulation triggering: another brick off the wall?

In recent years, there has been growing interest in understanding the dynamics of progesterone levels during the luteal phase after HCG-triggered ovulation. Recent studies have provided data showing a deviation from the natural ovulatory cycle, with peak progesterone concentrations occurring earlier and declining steadily thereafter, demonstrating that a fall in progesterone concentration early in the luteal phase was associated with lower rates of ongoing pregnancy. These findings highlight the importance of changes in progesterone concentration, rather than absolute concentrations, in determining optimal endometrial conditions. The disadvantages of HCG triggering, including the lack of a natural FSH surge and asynchronization between embryo age and endometrium receptivity, can be addressed by using gonadotrophin-releasing hormone agonist (GnRHa) triggering. GnRHa triggering induces both LH and FSH surges, ensures appropriate progesterone concentrations and offers flexibility in manipulating the luteal phase. Transitioning to GnRHa triggering could improve infertility treatment.

Association between female circulating heavy metal concentration and abortion: a systematic review and meta-analysis

Objective

This study aimed to evaluate the association between blood heavy metal (zinc (Zn), copper (Cu), lead (Pb), and cadmium (Cd)) concentrations and spontaneous abortion (SA) and recurrent pregnancy loss (RPL) and explore the possible endocrine dysfunction associated with it.

Methods

A literature search was performed in the PubMed, Embase, Cochrane Library, and Web of Science databases up to April 2023. The overall effects were expressed as the standard mean difference (SMD). Subgroup analysis was performed according to the type of abortion (SA or RPL). Stata 16.0 was utilized for data analysis.

Results

Based on the integrated findings, abortion women showed significantly lower Zn (SMD = -1.05, 95% CI: -1.74 to -0.36, p = 0.003) and Cu concentrations (SMD = -1.42, 95% CI: -1.97 to -0.87, p <0.001) and higher Pb (SMD = 1.47, 95% CI: 0.89-2.05, p <0.001) and Cd concentrations (SMD = 1.15, 95% CI: 0.45-1.85, p = 0.001) than normal pregnant women. Subgroup analysis showed that Zn and Cu deficiency and Cd and Pb exposure were significantly (p <0.05) associated with RPL, whereas Cu deficiency and Cd and Pb exposure were significantly (p <0.05) associated with SA.

Conclusion

Zn and Cu deficiencies and Pb and Cd exposure were associated with abortion. Endocrine dysfunction, such as insulin resistance, vitamin D insufficiency, and abnormal thyroid and sex hormone concentrations, is thought to be involved in heavy metal-related abortion.

Complementarity between Early Embryogenesis and Uterine Receptivity: Toward Integrative Approach to Female Infertility Management. Editorial to the Special Issue "Molecular Mechanisms of Human Oogenesis and Early Embryogenesis"

Two highly relevant papers were recently been published in the Special Issue of Molecular Sciences entitled "Molecular Mechanisms of Human Oogenesis and Early Embryogenesis" [...].

Molecular Clues to Understanding Causes of Human-Assisted Reproduction Treatment Failures and Possible Treatment Options

More than forty years after the first birth following in vitro fertilization (IVF), the success rates of IVF and of IVF-derived assisted reproduction techniques (ART) still remain relatively low. Interindividual differences between infertile couples and the nature of the problems underlying their infertility appear to be underestimated nowadays. Consequently, the molecular basis of each couple’s reproductive function and of its disturbances is needed to offer an individualized diagnostic and therapeutic approaches to each couple, instead of applying a standard or minimally adapted protocols to everybody. Interindividual differences include sperm and oocyte function and health status, early (preimplantation) embryonic development, the optimal window of uterine receptivity for the implanting embryo, the function of the corpus luteum as the main source of progesterone production during the first days of pregnancy, the timing of the subsequent luteoplacental shift in progesterone production, and aberrant reactions of the uterine immune cells to the implanting and recently implanted embryos. In this article, the molecular basis that underlies each of these abnormalities is reviewed and discussed, with the aim to design specific treatment options to be used for each of them.

Patient-tailored reproductive health care

Patient-tailored reproductive health care represents an important challenge for the current practice of infertility prevention, diagnosis and treatment. This approach is based on the concept of precision medicine, taking into account genetic, epigenetic, metabolic and lifestyle characteristics of each individual patient. Even though this goal is still far from being wholly achieved, some aspects can already be put into practice nowadays. Personalization can be based on a comprehensive analysis and synthesis of the patients' personal and familial history, taking into account outcomes of previous assisted reproduction technique (ART) attempts, if available, and confronting these data with the past and the latest clinical and laboratory examination outcomes. As to the male fertility status, there is an urgent need for the inclusion of an accurate diagnostic workup of infertile men leading to the choice of the most adequate follow-up for each particular pathological condition. The follow-up of women who have become pregnant as a result of the ART attempt has also to be personalized. This should be done taking into account both the basic data extracted from the patient's file and those derived from the experience gathered during the latest attempt. Last but not least, the individual condition of each couple has to be taken into account when counseling the patients as to the urgency of the actions to be taken to resolve their fertility problem.

New Aspects of Corpus Luteum Regulation in Physiological and Pathological Conditions: Involvement of Adipokines and Neuropeptides

The corpus luteum is a small gland of great importance because its proper functioning determines not only the appropriate course of the estrous/menstrual cycle and embryo implantation, but also the subsequent maintenance of pregnancy. Among the well-known regulators of luteal tissue functions, increasing attention is focused on the role of neuropeptides and adipose tissue hormones—adipokines. Growing evidence points to the expression of these factors in the corpus luteum of women and different animal species, and their involvement in corpus luteum formation, endocrine function, angiogenesis, cells proliferation, apoptosis, and finally, regression. In the present review, we summarize the current knowledge about the expression and role of adipokines, such as adiponectin, leptin, apelin, vaspin, visfatin, chemerin, and neuropeptides like ghrelin, orexins, kisspeptin, and phoenixin in the physiological regulation of the corpus luteum function, as well as their potential involvement in pathologies affecting the luteal cells that disrupt the estrous cycle.

Double HCG trigger improves recovery of oocytes in women with a paucifollicular response to ovarian stimulation: A pilot study

OBJECTIVE

To examine whether adding a second HCG trigger, 12.5 h after the first (36.5 h before ovarian puncture), can facilitate recovery of oocytes in women with a paucifollicular response to ovarian stimulation.

METHODS

A total of 85 women aged 35-42 years, with a paucifollicular response to ovarian stimulation and who had experienced a total failure of oocyte recovery after the standard HCG ovulation trigger 36.5 h before ovarian puncture, were subsequently treated by the same protocol but with the addition of a second HCG trigger 12.5 h later. The recovered oocytes were inseminated by intracytoplasmic sperm injection (ICSI) and all available embryos were transferred 3 days later.

RESULTS

The double trigger enabled recovery of cumulus oophorus cells from most of the follicles in the women who experienced failure of total recovery of oocytes after a single trigger. Fifteen patients became pregnant, and no signs of ovarian hyperstimulation syndrome were observed. Nine women delivered a healthy child.

CONCLUSION

In women aged 35-42 years with a paucifollicular response to ovarian stimulation, a double HCG trigger appears to improve the rate of oocyte recovery. The conclusion of this pilot study needs to be confirmed by larger prospective trials.